Help/Urgent - Informix Dynamic Server Indexing not working on Linux
Neil Edwards moved from SCO using SE to Informix Dynamic Server on Linux and found selects slower, with the same query time with or without an index. Michael Krzepkowski and Mike Aubury advised running update statistics; Mike also asked about the data copy method. Art S. Kagel pointed to his dostats.ec utility and SET EXPLAIN ON to check the plan. No outcome was reported.
Auto-generated by Claude from the posts below — may be imperfect; read the full thread.
On converting from SCO using SE, my select's are running slower. The query return time is the same whether I place an index on the search field or not. Can someone help me understand what's wrong? Thanks in advance. Neil Edwards -**** Posted from RemarQ, http://www.remarq.com/?a ****- Search and Read Usenet Discussions in your Browser - FREE -
HI! Have you run update statistics? Michael edwardscs@aol.com wrote: > On converting from SCO using SE, my select's are running slower. The query > return time is the same whether I > > place an index on the search field or not. Can someone help me understand > what's wrong? Thanks in advance. > > Neil Edwards > > -**** Posted from RemarQ, http://www.remarq.com/?a ****- > Search and Read Usenet Discussions in your Browser - FREE -
Make sure you run 'update statistics'.
Make sure your indexes make sense - how many rows are in the table, how many
different possible values etc..
Also - how did you copy the data across (dbimport/dbexport ?)
On Tue, 31 Aug 1999, edwardscs@aol.com wrote:
>On converting from SCO using SE, my select's are running slower. The query
>return time is the same whether I
>place an index on the search field or not. Can someone help me understand
>what's wrong? Thanks in advance.
>
>Neil Edwards
>
>
>
> -**** Posted from RemarQ, http://www.remarq.com/?a ****-
> Search and Read Usenet Discussions in your Browser - FREE -
Read the Performance Guide section on UPDATE STATISTICS. There is a least cost sequence of UPDATE STATS commands that one is encouraged to use to make sure the optimizer has the best stats it can get at the lowest cost in time to generate them. My dostats.ec program implements these recommendations so you can just get that, compile, and run it. Dostats.ec is part of the package utils2_ak from the IIUG Software Repository. Look for a new version with a few neat new features in the next week or so. I will make an announcement. Also try running the query under SET EXPLAIN ON; to see what query plan is being generated. Perhaps you have the wrong indexes? Art S. Kagel edwardscs@aol.com wrote: > > On converting from SCO using SE, my select's are running slower. The query > return time is the same whether I > > place an index on the search field or not. Can someone help me understand > what's wrong? Thanks in advance. > > Neil Edwards > > -**** Posted from RemarQ, http://www.remarq.com/?a ****- > Search and Read Usenet Discussions in your Browser - FREE -